[afis]

I think I have completed thorough research first, and have a few detailed questions or confirmation needs remaining. Thanks for any help.


1. When combinining separate UHF and VHF antennas, does it matter whether its outside on mast as soon as possible, or 25 ft later, just inside attic.


2. If I were to add FM via separate antenna, would there be too much loss of signal to combine with one of the other antennas then combine again with the remaining one? (better to run separately?)


3. Grounding - Bottom of galvanized steel tower, on cement block and alongside house, is now buried 5 ft because of landscaping change. I guess this is not an adequate ground of the mast and a wire should be run from it to house ground electrode?


4 Grounding - Sat dish, VHF, and separate UHF antennas all have cable coming into attic on side of house opposite where house electric panel is. ALL cables need static discharge/ground block I guess. Is it ok to ground these to a separate nearby ground rod so lang as I then then bond that to house electrode?


5 Grounding - When bonding per 4 above, do I understand correctly that I can join the new ground rod and mast at one end of the house and then run a single combined (and insulated) wire back into the INSIDE of the house till I can attach to house electrode?

 

[Scooper]

1. Doesn't matter. My joining of the 2 occurs in my attic, just to keep the connections out of the weather.


2. Not needed - the VHF antenna will pull in your FM quite nicely.


3. Should be done that way


4. Yes


5. When I get around to bonding mine, that's what I'll do. I guess you SHOULD run that snake outside the house.


I'm NOT a qualified electrician. Just a hobbyist like you.

 

[sregener]

Quote:

Originally posted by afis Is it ok to ground these to a separate nearby ground rod so lang as I then then bond that to house electrode?

My installer indicated that bonding two grounds together almost always created more problems than it solved, especially in areas with a lot of radio frequency interference.


It really doesn't matter how long the grounding connection is - the point isn't to provide lightning a good place to go. It is to make your antenna "neutral" from an electrical standpoint so it's no more attractive than the tree next door. Once you get a direct hit, everything's toast no matter what you did. Shoot, even a "near miss" can fry all the electronics in your house.

 

[greywolf]

From http://forums.nfpa.org:8081/necfaq/necsrch.htm

National Electrical Code - Search for "dish"

The information there also applies to antenna grounding.


The grounding conductor shall be permitted to be run either inside or outside the building. The grounding conductor shall not be smaller than No. 10 copper, No. 8 aluminum, or No. 17 copper-clad steel or bronze. A single grounding conductor shall be permitted for both protective and operating purposes. A bonding jumper not smaller than No. 6 copper or equivalent shall be connected between the radio and television equipment grounding electrode and the power grounding electrode system at the building or structure where separate electrodes are used.


My interpretation is that a bonding jumper inside the house is fine. I see no safety difference between an inside grounding wire and an inside bonding jumper. Always check your local codes though as they may differ from the NEC. You can also ask if uninsulated is ok as bare really identifies a ground wire and nobody is going to attach a hot wire to it.

 

[greywolf]

Quote:

Originally posted by sregener My installer indicated that bonding two grounds together almost always created more problems than it solved, especially in areas with a lot of radio frequency interference.

If the bond contact is solid, it will work fine. It looks like the NEC is requiring a separate, bonded rod for long runs to the main building ground in the latest revision. I seem to remember a separate rod is needed if the run is over 20ft but I'm sure we'll find out as this thread ages. I don't see what good it will do but codes need to be followed. Always check local codes as they can vary.

Quote:

Originally posted by sregener It really doesn't matter how long the grounding connection is - the point isn't to provide lightning a good place to go. It is to make your antenna "neutral" from an electrical standpoint so it's no more attractive than the tree next door. Once you get a direct hit, everything's toast no matter what you did. Shoot, even a "near miss" can fry all the electronics in your house.

Except maybe in the case of a really serious lightning protection system, that is so true. An antenna is not to be mistaken for a lightning rod. All that avoiding sharp bends and short, direct runs stuff is wishful thinking.

 

[afis]

Thanks all for the quick responses and valuable info.


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Quote from Greywolf

A bonding jumper not smaller than No. 6 copper or equivalent shall be connected between the radio and television equipment grounding electrode and the power grounding electrode system at the building or structure where separate electrodes are used.

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Im confused about what a "bonding jumper" is and what the "radio and tv electrode is." Could you expand a bit on these?

 

[greywolf]

If a ground rod is driven into the ground specifically for radio or TV antenna or dish to provide a ground point near the antenna, that is the radio/television ground electrode.


A bonding jumper is a heavy wire used to connect the radio/television ground electrode/rod to the main building ground.


If a separate ground rod for the radio/TV is not used, the above does not apply and the ground wires go directly to the main building ground.